JP7632938B2 - Circuit diagram reader, printed circuit board design device, and circuit diagram reader program - Google Patents

Description

The present disclosure relates to a circuit diagram reading device, a printed circuit board design device, and a circuit diagram reading program.

Conventionally, there has been known a design device that can place components that are to be placed close to each other on a printed circuit board so that the performance or characteristics of the electronic circuit can be fully exhibited. For example, the design device described in Patent Document 1 includes a knowledge pattern storage unit that stores the conditions for components that are to be placed close to each other on the printed circuit board as a knowledge pattern, a printed circuit board design information storage unit that stores components to be placed on the printed circuit board and wiring information between the components, a group classification means that determines whether each component stored in the printed circuit board design information storage unit satisfies the knowledge pattern stored in the knowledge pattern storage unit based on the wiring information, and classifies a collection of components that satisfy the knowledge pattern as one group, and a placement determination means that determines the placement on the printed circuit board by treating a group of components classified into one group as one placement element. The placement of components other than the group is based on the connection information in the printed circuit board design information storage unit.

Japanese Patent Application Publication No. 7-200655

However, the printed circuit board design device described in Patent Document 1 does not describe how to place components on a printed circuit board.

On the other hand, designers can determine the placement of components by referring to how the components are placed in a circuit diagram. This is because circuit diagrams are created so that the performance or characteristics of an electronic circuit can be demonstrated. It would be useful if the information in a circuit diagram could be read automatically and appropriately.

Therefore, the object of the present disclosure is to provide a circuit diagram reading device, a printed circuit board design device, and a circuit diagram reading program that can properly read circuit diagram information.

The circuit diagram reading device disclosed herein includes a component name detection unit that detects component names and their positions, or pin numbers and their positions, by detecting character strings and their positions included in an image of the circuit diagram; a component detection unit that detects components included in the image of the circuit diagram and registers the component types and component areas of the components in a detected components list; a line detection unit that detects lines included in the image of the circuit diagram; a wiring detection unit that detects wiring based on the detected lines; a pairing unit that pairs components and component names based on the positions of the component areas and the positions of the component names of the components registered in the detected components list; and a connection detection unit that detects connections between components registered in the detected components list and wiring in the image of the circuit diagram, identifies two components connected by one or more wiring, and, if the two identified components are also connected in the netlist, creates connection information indicating that the two identified components are connected.

This disclosure allows the circuit diagram information to be properly read.

FIG. 1 is a diagram showing the configuration of a printed circuit board design device 1 according to an embodiment. 11 is a diagram showing an example of a detection result of a part name. FIG. FIG. 13 is a diagram showing an example of a part detection result by YOLO. FIG. 13 is a diagram showing an example of component integration. 1A is a diagram showing an example of a straight line included in a component region, and FIG. 1B is a diagram showing a result of detecting wiring; 13A is a diagram showing another example of a straight line that is fitted inside a component region, and FIG. 13B is a diagram showing a result of detecting wiring; 1A is a diagram showing an example of a straight line passing through a component region, and FIG. 1B is a diagram showing a result of detecting wiring; FIG. 13 is a diagram showing an example of adding a line connecting two lines when a discontinuity is detected between the two lines. 1A is a diagram showing a circuit diagram, and FIG. 1B is a diagram showing a result of wiring detection in the circuit diagram of FIG. 1A is a diagram showing an example in which one component name is paired with a plurality of components of the same component type, and FIG. 1B is a diagram showing a component obtained by integrating the components in FIG. 1A is a diagram showing another example in which one part name is paired with a plurality of parts of the same part type, and FIG. 1B is a diagram showing a part obtained by integrating the parts in FIG. FIG. 13 is a diagram showing an example of expanding a part region. 1A is a diagram showing an example of a component with two pins and a net attribute of only power supply, and FIG. FIG. 13 is a diagram illustrating an example in which a circuit diagram group includes a plurality of components each having two pins and a net attribute of only power supply. 11A and 11B are diagrams for explaining examples of pairing and arrangement of child components; FIG. 13 is a diagram for explaining another example of pairing and arrangement of child components. FIG. FIG. 18 is a diagram showing an example of a layout based on the circuit diagram of FIG. 17. 2 is a flowchart showing a processing procedure of the printed circuit board design device 1 according to the embodiment. 1 is a diagram showing a hardware configuration of a printed circuit board design device 1.

Hereinafter, an embodiment will be described with reference to the drawings.
FIG. 1 is a diagram showing the configuration of a printed circuit board design device 1 according to an embodiment.

The printed circuit board design device 1 comprises a data input unit 2, a user I/F 4, a CAD (Computer Aided Design) unit 3, and a layout design unit 21.

The functions of the CAD unit 3 and the layout design unit 21 may be realized by the computer executing a printed circuit board design program stored in memory. The printed circuit board design program may be installed in the memory from an external source via a network. Alternatively, the printed circuit board design program may be installed in the memory via a portable recording medium.

The data input unit 2 inputs data such as circuit diagrams and netlists from the outside. The circuit diagrams are represented as PDF data, image data or CAD data.

The user I/F 4 accepts operations by the designer and displays the screen.
The CAD unit 3 creates CAD data in binary format according to the designer's operation using the data input from the data input unit 2. The CAD data includes a part name list, a pin number list, and the like.

The layout design unit 21 includes a conversion unit 5, a division unit 6, a net attribute setting unit 20, a circuit diagram group layout design unit 31, and an overall layout design unit 18. The circuit diagram group layout design unit 31 includes a straight line detection unit 7, a component name detection unit 8, a component detection unit 9, a component size distribution calculation unit 10, a unit distance calculation unit 11, a wiring detection unit 12, an intersection detection unit 19, a component-component name pairing unit 13, a connection detection unit 14, a component classification unit 15, a proximity block generation unit 16, and an in-proximity block component layout design unit 17.

The conversion unit 5 converts the circuit diagram into image data when the circuit diagram is in PDF format or CAD data. The conversion unit 5 converts the binary CAD data created based on the circuit diagram into text data, and creates a part name list in text data.

The net attribute setting unit 20 sets the attributes of a net that connects multiple components included in a circuit diagram. For example, the net attribute setting unit 20 sets the attributes of a net based on the name of the net included in the netlist.

The division unit 6 divides the circuit diagram into any processing units. If the circuit diagram spans multiple pages, the division unit 6 divides the circuit diagram into pages. If the circuit diagram is a large single page diagram, the division unit 6 divides it into meaningful units (blocks). The meaningful units can be set by the designer. By defining rules that stipulate meaningful units in the circuit diagram, the division unit 6 can also automatically divide the circuit diagram into meaningful units. The following processing is performed for each divided unit. The divided units are called circuit diagram groups.

The circuit diagram group layout design unit 31 performs layout design of components within a circuit diagram group.
The line detector 7 detects lines in each circuit diagram group. For example, a Hough transform can be used as the line detection algorithm. In the Hough transform, unnecessary calculations can be eliminated by narrowing down the angle of the line to be detected to a predetermined range. This is because in general circuit diagrams, wiring is often represented by vertical or horizontal lines. In special circuit diagrams, lines of any selected angle may be detected.

If the circuit diagram is PDF data or CAD data, the component name detection unit 8 detects the character string embedded in the data and its position. If the circuit diagram is image data, the component name detection unit 8 detects the character string included in the image of the circuit diagram and its position by using a known character recognition algorithm.

If the detected character string is registered in the component name list, the component name detection unit 8 identifies the detected character string as a component name and identifies the position of the character string as the position of the component name. If the detected character string is registered in the pin number list, the component name detection unit 8 identifies the detected character string as a pin number and identifies the position of the character string as the position of the pin number. If the detected character string exists in the component area of the IC and is registered in the pin number list, the component name detection unit 8 may identify the detected character string as a pin number and identify the position of the character string as the position of the pin number.

The part name detection unit 8 may be able to deal with variations in spelling rather than performing a pure match search. For example, if the detected character string includes a character string that represents the physical properties of the part, the part name detection unit 8 may compare the character string excluding the character string with the part name list or the pin number list. Character strings that represent the physical properties of the part include, for example, resistance, capacitance, voltage, and inductance. For example, in the case of the detected character string "R1 10k", the part name detection unit 8 compares "R1" with the part name list.

When one component is included on multiple sheets and similar character strings corresponding to the component exist on each sheet, the component name detection unit 8 may identify the common part of the character strings on each sheet as the component name. When "IC1-1" is written on the circuit diagram on the first divided sheet and "IC1-2" is written on the circuit diagram on the second divided sheet, the component name detection unit 8 identifies the component name as "IC1."

If the detected character string is not registered in the component name list or pin number list, the component name detection unit 8 does not identify the detected character string as a component name or pin number. This prevents character strings unrelated to the circuit, such as comments, authors, and dates, from being detected as component names or pin numbers.

FIG. 2 shows an example of the result of detecting part names.
The part names detected are IC52, R95, R98, R72, R74, R46, C24, and C25.

The component detection unit 9 detects components contained in the circuit diagram image and registers the component type and component area of the components in a detected component list.

The component detection unit 9 detects components included in the circuit diagram using a deep learning algorithm such as CNN (Convolutional Neural Network) or YOLO (You-Only-Look-Once). Along with the detection of the components, the component type of the component and the component area of the component on the circuit diagram are detected. The components are described in the circuit diagram as circuit diagram symbols representing the component type. The detected components are registered in a detected components list. The component area is, for example, a rectangular area. The detected components list defines the "component type" and "component area" of the detected components. The "component type" may include multiple candidates and the accuracy of each candidate.

Because the sizes of "ICs and connectors, etc." and "resistors and capacitors, etc." depicted on the circuit diagram can be extremely different, the component detection unit 9 may improve detection accuracy by using an image of the circuit diagram and an image obtained by enlarging the image of the circuit diagram and dividing it into specified regions. The component detection unit 9 may further improve detection accuracy by using an image of the circuit diagram, an image obtained by flipping the image of the circuit diagram horizontally, and an image obtained by flipping the image vertically, and by summing or majority voting (ensemble) of the detection results.

FIG. 3 shows an example of a part detection result by YOLO.
Five resistors R, one IC, and two capacitors are detected. The numbers in the figure indicate the accuracy.

The part detection unit 9 may not register the part type and part area of the detected part in the detected part list if the part area of the detected part does not contact the straight line detected by the straight line detection unit 7. The part detection unit 9 may not register the part type and part area of the detected part in the detected part list if the part name does not exist within a predetermined distance from the "part area" of the detected part in the image of the circuit diagram. This is because there is a high possibility of erroneous detection.

The component detection unit 9 may estimate multiple candidates as the component type of the detected component, and select one component type from the multiple candidates based on the component name closest to the center position of the component area. When the "component type" of the detected component is "IC" or "C", and the component name closest to the "component area" of the detected component in the image of the circuit diagram is "IC**", the component detection unit 9 may determine "IC" as the "component type" of the detected component.

When the "part type" of a detected part includes multiple candidates, the part detection unit 9 may determine the one with the highest degree of certainty as the "part type." For example, when the degree of certainty of the candidate "IC" is 90% and the degree of certainty of the candidate "C" is 10%, the part detection unit 9 determines "IC" as the part type.

The component size distribution calculation unit 10 obtains the size distribution of components for each type of component detected in a portion of the circuit diagram (for example, the first few sheets out of multiple sheets) and calculates the median size. Different circuit diagrams have different component sizes and scales, but the same component is rarely drawn at extremely different sizes within a single circuit diagram. By obtaining the size distribution of each component in the circuit diagram, it is possible to obtain a rough scale, such as the fact that this component is often drawn at around "A x B pixels" in the circuit diagram. For example, the median size of a capacitor can be obtained as 5 x 5 pixels, and the median size of an IC can be obtained as 100 x 100 pixels.

When the "part type" of a detected part includes multiple candidates in other parts of the circuit diagram (e.g., sheets other than the first few sheets of the multiple sheets), the part detection unit 9 may determine the "part type" of the detected part based on the size distribution by part type. For example, in a 5x5 part area, when the probability of the candidate "IC" is 50%, the probability of the candidate "C" is 10%, the median of the size distribution of "IC" is "10x10", and the median of the size distribution of "C" is "5x5", the part detection unit 9 may determine "C" as the "part type".

FIG. 4 is a diagram showing an example of component integration.
The part detection unit 9 detects part A with part type "X" and part area "RA1", detects part B with part type "X" and part area "RA2", and when part of part area RA1 overlaps part of part area RA2, it considers one part C to have been detected. The part detection unit 9 sets the "part type" of part C to X, and the "part area" to area RA3 covering part area RA1 and part area RA2.

The unit distance calculation unit 11 calculates the median of the size distribution of one or more R (resistor), L (coil), and C (capacitor) component areas registered in the detection component list as the unit distance. Since the scale differs depending on the circuit diagram, the reference value for various processing decisions is set based on the unit distance. R, L, and C are used as units of distance because R, L, and C are included more frequently in circuit diagrams than active elements. In addition, the circuit diagram symbols for R, L, and C have less variation in size and are often written smaller than the circuit diagram symbols for active elements. For example, the unit distance is used as a criterion to determine whether or not to place a child component close to a parent component.

The intersection detection unit 19 detects connection points (intersections) of wiring lines represented by black circles on the circuit diagram.
The wiring detection unit 12 detects wiring based on the straight lines detected by the straight line detection unit 7. The wiring detection unit 12 does not regard as wiring, among the straight lines detected by the straight line detection unit 7, those straight lines included in the component area of the component detected by the component detection unit 9. This is because the straight lines included in the detected component area are straight lines that constitute the component.

Figure 5(a) shows an example of a straight line included in a component area. Figure 5(b) shows the results of wiring detection.

The straight lines L1, L2, L3, and L4 are detected by the straight line detection unit 7. The wiring detection unit 12 does not consider the straight lines L3 and L4 contained within the component area RA to be wiring. The wiring detection unit 12 does not consider the parts of the straight lines L1 and L2 that are internally aligned with the component area RA to be wiring.

Figure 6(a) shows another example of a straight line that is internally aligned with a component area. Figure 6(b) shows the results of wiring detection.

Lines L1, L2, L3, and L4 are detected by the line detection unit 7. The wiring detection unit 12 does not consider the line L1 contained within the component region RB to be wiring. The wiring detection unit 12 does not consider the parts of the lines L2, L3, and L4 that are internally aligned with the component region RB to be wiring.

Components such as coils may have "wiring extending from the left and right sides of the component" and "straight lines within the component" (straight lines contained within the component) written in succession. If these straight lines are treated as one wiring, the left and right terminals are treated as being shorted. If a straight line detected by the straight line detection unit 7 passes through a component area, the wiring detection unit 12 divides the line with the component area as the center, and treats one straight line outside the component area as one wiring, and the other straight line outside the component area as a different wiring.

Figure 7(a) shows an example of a straight line passing through a component area. Figure 7(b) shows the results of wiring detection.

The straight line detection unit 7 detects a straight line L1 that passes through the component area RC. The wiring detection unit 12 divides the straight line L1 with the component area RC as the center, and treats one straight line L1A outside the component area RC as one wiring, and the other straight line L1B outside the component area RC as another wiring.

The wiring detection unit 12 does not consider as wiring any straight line detected by the line detection unit 7 that does not intersect with any of the intersections, components, or skip signal symbols. This is because wiring is written by intersecting with either an intersection, component, or skip signal symbol. A skip signal symbol is a symbol that represents a connection to another location on the circuit diagram. If a skip signal symbol S is written at position X on the circuit diagram and the same skip signal symbol S is written at position Y on the circuit diagram, this represents the presence of a wiring that is not written on the circuit diagram but connects position X and position Y on the circuit diagram.

When a second line is present within a circle with a radius that is a predetermined multiple of the unit distance and centered on the end point of a first line detected by the line detection unit 7, the wiring detection unit 12 adds the shortest line connecting the end point of the first line and the second line for wiring detection. This is because the detection accuracy of short lines decreases with the Hough transform, and two lines that are actually connected on the circuit diagram may be detected as if they are disconnected.

Figure 8 shows an example of adding a line connecting two lines when the two lines are detected as being disconnected.

Since another straight line L2 exists within a circle CR1 whose center is the end point EN1 of the straight line L1 and whose radius is a specified multiple of the unit distance, the shortest straight line L3 that connects the end point EN1 and the straight line L2 is added. As a result, the straight lines L1, L3, and L2 are each detected as wiring.

Figure 9(a) is a diagram showing a circuit diagram. Figure 9(b) is a diagram showing the results of wiring detection in the circuit diagram of Figure 9(a). The lines written in bold in Figure 9(b) are the detected wiring.

The part-part name pairing unit 13 pairs a part registered in the detected parts list with a part name. The part-part name pairing unit 13 pairs a part with a part name based on the center position of the part area and the center position of the part name. Specifically, the part-part name pairing unit 13 pairs a part with the part name having a center position closest to the center position of the part's part area.

When multiple part names exist within a specified distance from the center position of the part's part area, the part-part name pairing unit 13 pairs the part with one of the multiple part names that is of the same type as the part type of the part.

When one part name is paired with multiple parts of the same part type, the part-part name pairing unit 13 merges the multiple parts into one part. The part-part name pairing unit 13 determines the smallest rectangle that includes the part areas of the multiple parts as the part area of the merged part.

Figure 10(a) is a diagram showing an example in which one component name is paired with multiple components of the same component type. Figure 10(b) is a diagram showing a component in which the components in Figure 10(a) are integrated. One component name "IC1" is paired with two components A and B of the same component type. The two components A and B are integrated into one component C, and component area R1 of component A and component area R2 of component B are integrated. The component area of the integrated one component C is RC.

Figure 11(a) is a diagram showing another example in which one part name is paired with multiple parts of the same part type. Figure 11(b) is a diagram showing parts obtained by integrating the parts in Figure 11(a). One part name "IC2" is paired with three parts A, B, and C of the same part type. The three parts A, B, and C are integrated into one part D, and part region R1 of part A, part region R2 of part B, and part region R3 of part C are integrated. The part region of the integrated part D is RC.

The connection detection unit 14 detects the connection between the parts registered in the detection parts list and the wiring in the image of the circuit diagram. The connection detection unit 14 detects that the parts and wiring are connected when the part area of the parts and the wiring are connected. On the circuit diagram, short leader lines extending from the parts, such as the short diagonal leader lines of the transistor, are often missed by the straight line detection. Even if the connection of the parts on the circuit diagram is traced using the results of the wiring detection, it is interrupted at the leader line. In order to solve such a problem, the connection detection unit 14 expands the part areas of all the parts registered in the detection parts list by a predetermined multiple of the unit distance in the vertical and horizontal directions. As a result, the part area is expanded so as to surround the area of the leader line. The connection detection unit 14 may detect that the parts and wiring are connected when the expanded part area and the wiring are connected.

FIG. 12 is a diagram showing an example of expanding a part region.
The component region R1 is expanded to generate an extended component region R1A. The connections between the extended component region R1A and the wires W1, W2, and W3 are detected. The connections between the extended component region R2A and the wires W3, W4, W5, and W6 are detected.

The connection detection unit 14 identifies two components (a first component and a second component) that are connected by one or more wirings. The connection detection unit 14 checks whether the two identified components are also connected in the netlist. The reason for referencing the netlist in this way is that when two lines intersect on a circuit diagram, there are cases where the two wirings are connected and cases where the two wirings are not connected. When the two wirings are connected, an intersection exists. When the two identified components are also connected in the netlist, the connection detection unit 14 creates connection information indicating that the two components (a first component and a second component) are connected.

When the X pin of a first component is connected to a second component by one or more wires, the connection detection unit 14 creates connection information indicating that the X pin of the first component is connected to the second component.

The component classification unit 15 classifies the multiple components registered in the detection component list into parent components, child components, and other components based on the component type. Parent components are, for example, ICs. Child components are, for example, oscillators, bypass capacitors, damping resistors, electrolytic capacitors, and termination resistors.

When there is no part of the component type specified as a parent part among the multiple components registered in the detected component list in one circuit diagram group, the component classification unit 15 sets the parent part according to the following rules.

The component classification unit 15 refers to the netlist and classifies, among the multiple components registered in the detection component list, those components that have two pins and whose net attribute is only power supply, as parent components.

Figure 13(a) is a diagram showing an example of a component with two pins and a net attribute of power supply only. Figure 13(b) is a diagram showing an example of a netlist. L1 has two pins and a net attribute of power supply 5V, 5VA only. Therefore, L1 is set as the parent component, and C1 and C2 are directly connected to the parent component, and are therefore set as child components of L1.

When there are multiple two-pin components with only power as a net attribute among the multiple components registered in the detected components list, the component classification unit 15 sets those components as parent components. The component classification unit 15 sets a component that is directly or indirectly connected to a parent component as a child component of that parent component. The component classification unit 15 sets a part that is directly or indirectly connected to multiple parent components as a child component of the parent part that is closest to that part among the connected parent parts.

Figure 14 shows an example where there are multiple components with two pins and only power net attributes within a circuit diagram group.

L1 has two pins and its net attributes are only power supply 5V, 5VA. Therefore, L1 is set as a parent component. C1 is directly connected to L1, so C1 is set as a child component of L1. L2 has two pins and its net attributes are only power supply 5V, 5VB. Therefore, L2 is set as a parent component. C2 is directly connected to L2, so C2 is set as a child component of L2. C3 is connected to L1 and L2, but the distance between C3 and L2 is shorter than the distance between C3 and L1, so C3 is set as a child component of L2.

The proximity block generation unit 16 generates a proximity block including a parent part and one or more child parts that are directly or indirectly connected to the parent part based on the connection information.

Based on the connection information, the adjacent block component placement design unit 17 pairs a pin of a parent component with a child component that connects to the pin of the parent component, or pairs a pin of a child component with another child component that connects to the pin of the child component.

When a pin of a parent component is paired with multiple child components, the adjacent block component placement design unit 17 determines the positions of the multiple child components based on the position of the pin of the parent component in the circuit diagram and the positions of the multiple child components. The adjacent block component placement design unit 17 places a child component closer to the pin of the parent component in the circuit diagram, the closer the child component is to the pin of the parent component.

FIG. 15 is a diagram for explaining an example of pairing and arrangement of child components.
Pin P4 of IC1 is connected to child component C3 and child component C4. Pin P4 of parent component IC1 is paired with child components C3 and C4. Child component C4 is detected from the circuit diagram as being closer to pin P4 of parent component IC1 than child component C3, so child component C4 is placed closer to pin P4 of parent component IC1 than child component C3.

Pin P2 of parent component IC1 is connected to pin P7 of child component X and child component C1. Pin P3 of parent component IC1 is connected to pin P6 of child component X and child component C2. Pin P8 of child component X is connected to child component C1 and child component C2. Pin P5 of child component X is connected to child component C1 and child component C2.

Pin P2 of parent component IC1 is paired with child component X, and pin P3 of parent component IC1 is paired with child component X. From the circuit diagram, the distance between child component X and pin P2 of parent component IC1 and the distance between child component X and pin P3 of parent component IC1 are approximately the same, so child component X is placed near pins P2 and P3 of parent component IC1.

Pin P7 of child component X is paired with child component C1, and pin P8 of child component X is paired with child component C1. From the circuit diagram, the distance between child component C1 and pin P7 of child component X is approximately the same as the distance between child component C1 and pin P8 of child component X, so child component C1 is placed near pins P7 and P8 of child component X.

Pin P5 of child component X is paired with child component C2, and pin P6 of child component X is paired with child component C2. From the circuit diagram, the distance between child component C2 and pin P5 of child component X is approximately the same as the distance between child component C2 and pin P6 of child component X, so child component C2 is placed near pins P5 and P6 of child component X.

When multiple pins of a parent component are paired with a child component, the adjacent block component placement design unit 17 determines the position of the child component based on the positions of the multiple pins of the parent component detected in the circuit diagram and the position of the child component. The adjacent block component placement design unit 17 places the child component near the pin of the parent component that is closest to the child component in the circuit diagram.

FIG. 16 is a diagram for explaining another example of pairing and arrangement of child components.
A pin P1 of the parent component IC1 is paired with a child component C1, and a pin P2 of the parent component IC1 is paired with a child component C1. Since it is detected from the circuit diagram that the child component C1 is closer to the pin P2 of the parent component IC1 than to the pin P1 of the parent component IC1, the child component C1 is placed at a position closer to the pin P2 of the parent component IC1.

Figure 17 is a diagram showing a circuit diagram. Figure 18 is a diagram showing an example of layout based on the circuit diagram of Figure 17.

C79 is placed near the 12th pin of the connected IC15, C80 is placed near the 13th pin of the connected IC15, C81 is placed near the 16th pin of the connected IC15, and C82 is placed near the 17th pin of the connected IC15.

C90 is placed near the 35th pin of the connected IC15, C91 is placed near the 34th pin of the connected IC15, C92 is placed near the 29th pin of the connected IC15, and C93 is placed near the 28th pin of the connected IC15.

X4 is placed near the sixth and seventh pins of the connected IC 15. C18 is placed near the first pin of the connected X4, and C19 is placed near the third pin of the connected X4.

C83, C84, and C85 are placed near either pin 5, pin 10, or pin 32 of the connected IC15.

R33 is placed near pin 36 of IC 15 to be connected (back side of the board), R34 is placed near pin 26 of IC 15 to be connected (back side of the board), R35 is placed near pin 25 of IC 15 to be connected (back side of the board), R36 is placed near pin 24 of IC 15 to be connected (back side of the board), and R37 is placed near pin 21 of IC 15 to be connected (back side of the board).

C78 is placed near the C84 to which it is connected. FL6 is placed near the C78 to which it is connected.

The overall layout design unit 18 determines the layout of one or more adjacent blocks included in the circuit diagram group within the circuit diagram group, obtains the area of the circuit diagram group on the board, and places one or more adjacent blocks included in the circuit diagram group in the obtained area of the circuit diagram group.

Figure 19 is a flowchart showing the processing procedure of the printed circuit board design device 1 of the embodiment.

In step S101, the data input unit 2 inputs data such as a circuit diagram and a netlist from the outside.

In step S102, the CAD unit 3 creates binary format CAD data including a component name list and a pin number list using the data input from the data input unit 2 in accordance with the designer's operations.

In step S103, if the circuit diagram is PDF format data or CAD data, the conversion unit 5 converts it into image data. The conversion unit 5 converts the binary format CAD data created based on the circuit diagram into text data, and creates a part name list and a pin number list in text data.

In step S104, the division unit 6 divides the circuit diagram into arbitrary processing units and creates multiple circuit diagram groups.

In step S105, the line detection unit 7 detects lines in the circuit diagram for each circuit diagram group.

In step S106, the component name detection unit 8 detects the component name and its position, or the pin number and its position, by detecting the character string contained in the circuit diagram image and the position of that character string in each circuit diagram group.

In step S107, the component detection unit 9 detects components included in the circuit diagram image in each circuit diagram group, and registers the component types and component areas of the components in a detected component list. The component size distribution calculation unit 10 calculates the median size of the component areas of the components detected in the part of the circuit diagram for each component type.

In step S108, the unit distance calculation unit 11 calculates the median of the sizes of one or more resistors, coils, and capacitors registered in the detection component list as the unit distance.

In step S109, the component-component name pairing unit 13 pairs a component with a component name in each circuit diagram group based on the position of the component area of the component registered in the detected component list and the position of the component name.

In step S110, the wiring detection unit 12 detects wiring in each circuit diagram group based on the detected straight lines.

In step S111, the intersection detection unit 19 detects wiring connection points (intersections) represented by black circles on the circuit diagram in each circuit diagram group.

In step S112, the connection detection unit 14 detects connections between components registered in the detected components list in the circuit diagram image and wiring in each circuit diagram group, identifies two components connected by one or more wiring, and, if the two identified components are also connected in the netlist, creates connection information indicating that the two identified components are connected.

In step S113, the component classification unit 15 classifies the components registered in the detected components list in each circuit diagram group into parent components, child components, and other components.

In step S114, the proximity block generation unit 16 generates a proximity block for each circuit diagram group based on the connection information, the proximity block including a parent component and one or more child components that are directly or indirectly connected to the parent component.

In step S115, the adjacent block component placement design unit 17 places components within adjacent blocks in each circuit diagram group.

In step S116, the overall layout design unit 18 determines the placement of one or more adjacent blocks included in the circuit diagram group within the circuit diagram group, obtains the area of the circuit diagram group on the board, and places one or more adjacent blocks included in the circuit diagram group in the obtained area of the circuit diagram group.

Figure 20 is a diagram showing the hardware configuration of the printed circuit board design device 1. The printed circuit board design device 1 can be realized by a known personal computer or the like. The printed circuit board design device 1 includes a processor 100, a display device 200 such as an LCD display, an input device 300 such as a keyboard and a mouse, an internal storage device 400 such as a memory, an external storage device 500 such as a hard disk or a portable recording medium, and a communication device 600.

The input device 300 accepts input from a designer. The communication device 600 can receive a printed circuit board design program and data from the outside via the Internet, etc. The external storage device 500 can store the printed circuit board design program and data. The internal storage device 400 stores the printed circuit board design program and data transferred from the communication device 600 or the external storage device 500. The processor 100 displays a circuit diagram, proximity blocks, a detected parts list, a netlist, etc. on the display device 200. The processor 100 executes the printed circuit board design program stored in the internal storage device 400. This causes processing to be performed according to the flowchart of FIG. 19.

Variant examples.
The present disclosure is not limited to the above-described embodiment, and includes, for example, the following modifications.

(1) Circuit Diagram Group In the above embodiment, the units into which the circuit diagram is divided by the dividing unit 6 are regarded as circuit diagram groups that serve as units of layout design, but this is not limiting. For example, a circuit diagram having a plurality of units into which the circuit diagram is divided may be regarded as a circuit diagram group.

(2) Printed Circuit Board Design Device In the above embodiment, the printed circuit board design device includes all of the components of the layout design unit 21 in Fig. 1, but is not limited to this. For example, the printed circuit board design device may include only the conversion unit 5, the division unit 6, the net attribute setting unit 20, and the line detection unit 7, the component name detection unit 8, the component detection unit 9, the wiring detection unit 12, the component-component name pairing unit 13, the connection detection unit 14, the intersection detection unit 19, the component size distribution calculation unit 10, and the unit distance calculation unit 11 included in the circuit diagram group layout design unit 31. In this case, the printed circuit board design device functions as a circuit diagram reading device.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present disclosure is indicated by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

1 Printed circuit board design device, 2 Data input unit, 3 CAD unit, 4 User I/F, 5 Conversion unit, 6 Division unit, 7 Line detection unit, 8 Component name detection unit, 9 Component detection unit, 10 Component size distribution calculation unit, 11 Unit distance calculation unit, 12 Wiring detection unit, 13 Component name pairing unit, 14 Connection detection unit, 15 Component classification unit, 16 Proximal block generation unit, 17 Proximal block component layout design unit, 18 Overall layout design unit, 19 Intersection detection unit, 20 Net attribute setting unit, 21 Layout design unit, 31 Circuit diagram group layout design unit, 100 Processor, 200 Display unit, 300 Input unit, 400 Internal storage unit, 500 External storage unit, 600 Communication unit.

Claims (21)

a component name detection unit that detects a character string included in an image of a circuit diagram and a position of the character string to thereby detect a component name and a position of the component name, or a pin number and a position of the pin number;
a component detection unit that detects components included in the image of the circuit diagram and registers the component types and component areas of the components in a detected components list;
a straight line detection unit that detects straight lines included in the image of the circuit diagram;
a wiring detection unit that detects wiring based on the detected straight lines;
a pairing unit that pairs the component and the component name based on a position of the component area of the component registered in the detected component list and a position of the component name;
a connection detection unit that detects connections between the components registered in the detected components list and the wiring in an image of the circuit diagram, identifies two components connected by one or more wiring, and, if the two identified components are also connected in a netlist, creates connection information indicating that the two identified components are connected. The circuit diagram reading device of claim 1, wherein the part name detection unit, if the detected character string is registered in a part name list, identifies the detected character string as a part name and identifies the position of the character string as the position of the part name, and, if the detected character string is registered in a pin number list, identifies the detected character string as a pin number and identifies the position of the character string as the position of the pin number. The circuit diagram reading device of claim 2, wherein the part name detection unit deletes a character string representing the physical properties of the part from the detected character string, and compares the deleted character string with the part name list or the pin number list. The circuit diagram reading device of claim 1, wherein the component detection unit detects component types and component areas based on a deep learning algorithm. The circuit diagram reading device of claim 4, wherein the component detection unit estimates multiple candidates as the component type of the detected component, and selects one component type from the multiple candidates based on the component name closest to the center position of the component area. a component size distribution calculation unit that calculates a median value of the size of component areas of components detected in a portion of the circuit diagram for each type of component;
5. The circuit diagram reading device according to claim 4, wherein the component detection unit estimates a plurality of candidates as the component types of the components detected in the other portion of the circuit diagram, and selects one component type from the plurality of candidates based on a median value of the size of the component area for each type of component. A circuit diagram reading device as described in claim 4, wherein the component detection unit does not register the component type and component area of the detected component in the detected component list if the component area of the detected component does not contact the straight line detected by the straight line detection unit. A circuit diagram reading device as described in claim 4, wherein the component detection unit does not register the component type and component area of a detected component in the detected component list if the component name is not present in the circuit diagram image within a predetermined distance from the component area of the detected component. The circuit diagram reading device of claim 1, wherein the wiring detection unit does not consider, as wiring, straight lines detected by the straight line detection unit that are contained within the component area of the detected component. The circuit diagram reading device of claim 1, wherein the wiring detection unit does not regard as wiring any straight line detected by the straight line detection unit that does not intersect with any of the symbols representing intersections, component areas, or connections to other parts of the circuit diagram. A circuit diagram reading device as described in claim 1, further comprising a unit distance calculation unit that calculates the median value of the size of one or more resistors, coils, and capacitors registered in the detection component list as a unit distance. The circuit diagram reading device of claim 11, wherein the wiring detection unit adds the shortest straight line connecting the end point of the first straight line and the second straight line for wiring detection when a second straight line is present within a circle having a radius that is a predetermined multiple of the unit distance and centered on the end point of the first straight line detected by the straight line detection unit. The circuit diagram reading device of claim 1, wherein the pairing unit pairs the component with a component name having a center position closest to the center position of the component area of the component. The circuit diagram reading device of claim 1, wherein, when multiple component names are present within a predetermined distance from the center position of the component area of the component, the pairing unit pairs the component with one of the multiple component names that is of the same type as the component type of the component. The circuit diagram reading device of claim 13, wherein the pairing unit merges multiple components into one component when one component name is paired with multiple components of the same component type. The circuit diagram reading device of claim 11, wherein the connection detection unit expands the component areas of all components registered in the detection component list by a predetermined multiple of a unit distance in the vertical and horizontal directions, and detects that the components and wiring are connected when the expanded component areas are connected to wiring. A circuit diagram reader according to any one of claims 1 to 16,
a parts classification unit that classifies the parts registered in the detected parts list into parent parts, child parts, and other parts;
a proximity block generator that generates a proximity block including a parent part and one or more child parts directly or indirectly connected to the parent part based on the connection information;
and a proximity block in-component layout design unit that arranges components in the proximity block. The printed circuit board design device of claim 17, wherein the component classification unit classifies the components registered in the detected components list into the parent components, the child components, and the other components based on the component type of the components. The printed circuit board design device of claim 18, wherein, when there is no component of a component type designated as a parent component among the multiple components registered in the detected components list, the component classification unit refers to a netlist and classifies a component among the multiple components that has two pins and a net attribute of only power supply as a parent component. The printed circuit board design device of claim 19, wherein the component classification unit classifies the component with the greatest number of pins among the multiple components registered in the detected component list as a parent component when there is no component with two pins and a net attribute of power only among the multiple components registered in the detected component list. On the computer,
A step of detecting a character string included in an image of a circuit diagram and a position of the character string, thereby detecting a component name and a position of the component name, or a pin number and a position of the pin number;
detecting components included in the image of the circuit diagram, and registering the component types and component areas of the components in a detected components list;
detecting straight lines included in the image of the circuit diagram;
detecting wiring based on the detected straight lines;
pairing the component with the component name based on a position of the component area of the component registered in the detected component list and a position of the component name;
a step of detecting connections between the components registered in the detected components list and the wiring in an image of a circuit diagram, identifying two components connected by one or more wiring, and, if the two identified components are also connected in a netlist, creating connection information indicating that the two identified components are connected.

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